Roofing in Conshohocken, PA

A mill town of row homes on a hillside

Conshohocken was laid out as a borough in 1850 on the hill above a bend in the Schuylkill. The mills took the waterfront, and the workers' houses went up the slope in a grid, with Fayette Street climbing from the river to the center of town. Most of what's left from that era is row homes and twins, packed shoulder to shoulder.

A lot of those row homes have a low-slope roof over the main house, sometimes with a short shingled or mansard front facing the street, and a lower flat roof over the back kitchen. Under it, on the older houses, the deck is often wood planks rather than plywood. Newer townhomes and apartments near the river have their own roofs, usually managed by an HOA or building owner.

Ask most Conshohocken row-home owners what their roof is made of and they don't know, because they've never seen it. That's fine. It just means the first visit is usually about finding out what's up there and how long it has left.

When your roof is one piece of a long row

The seam between you and your neighbor

On a row of low-slope roofs, each house usually got redone at a different time with a different material: EPDM rubber on one, modified bitumen on the next, an old coated roof after that. Where two of them meet is the weakest point in the whole row. A leak at the party line can come from your side, your neighbor's side, or the joint between them, and the stain may show up in either house.

Parapet walls and coping

Some rows have low brick walls, called parapets, between houses or along the front. The top of the wall, the coping, has to shed water, and the roof membrane has to run up the wall and be sealed under a cap or into the brick. When the mortar on the parapet cracks, water gets into the wall from above and shows up on an upstairs ceiling or wall, even though the roof surface looks fine.

Ponding water

Flat roofs aren't truly flat. They're built with a slight pitch toward a drain, a scupper or the gutter at the back. When an old plank deck sags, or a drain clogs, water sits in puddles for days. Standing water ages the roof surface faster and finds every weak seam.

The back kitchen roof

The lower roof over the back of the house takes all the water that runs off the main roof above it, plus its own. Where it meets the back wall of the main house is a classic leak spot, especially if the flashing there is just a smear of tar.

Talk to the neighbors: If the house next door has the same age roof, doing both at the same time gives one continuous roof with no seam at the party line, and it's often cheaper per house. If only yours is being done, ask how the joint with theirs will be sealed.

A twice-a-year check for a row-home flat roof

Many Conshohocken row homes have a hatch or a back window that gives you a view of the roof. Only go out on it if it's dry, the deck feels solid, and you're comfortable doing it. Otherwise, look from the window or take photos with your phone held out.

• Puddles still there two days after rain
• Blisters or bubbles in the roof surface, or cracks like dried mud
• Seams lifting, especially at the party line with your neighbor
• A clogged drain, scupper or back gutter
• Cracked mortar or loose coping on any parapet wall
• Bare black patches where the silver or white coating has worn off

Clear leaves and debris from the drain or scupper yourself if you can do it safely. For the rest, regular upkeep makes a big difference: a modified bitumen torch-down roof lasts about 10 to 20+ years depending on maintenance. We recommend re-sealing the flashing and a fresh reflective coating every three years. See flat roofing for what that involves.

Storms, the river and your downspouts

During Hurricane Ida in 2021, the Schuylkill rose higher than it had in well over a century and flooded the lower blocks of Conshohocken. A roof can't do anything about the river. But in a heavy rain anywhere in the borough, make sure your roof's water goes where it should: into a working downspout that carries it away from the house, not down the back wall or into a neighbor's yard.

If wind lifts a section of roof or a storm opens a seam and water comes in, call us any time. We tarp or temporarily seal it to stop the water, usually the same day, then schedule the permanent fix. Read more on emergency roof repair.

A family roofer who works on row homes

Armstrong Roofing is a family-owned company based in Horsham, a short drive from Conshohocken. Owner Jim Armstrong personally oversees every job, and the team brings 50+ years of combined roofing experience. We install EPDM and modified bitumen flat-roof systems as well as architectural shingles for sloped fronts and twins.

• Free inspection with photos, including the party-line seams and any parapet walls
• Written, line-item estimate before any work starts
• PA license #PA164826, general liability and workers' compensation insurance
• BBB A+ rated, GAF certified, 5.0 rating from 200+ Google reviews

We also work in nearby Plymouth Meeting, Blue Bell and across Montgomery County.

What it usually costs

Row-home roofs are small, so most Conshohocken flat-roof replacements sit in the lower half of the range. A sagging plank deck, parapet work or a shared job with the neighbor change the number.

• Flat Roof Repair: $350 – $1,800
• Flat roof maintenance (every 3 years): $350 and up
• Flat Roof Installation: $4,000 – $15,000
• Roof Repair: $350 – $2,500
• Emergency Roof Repair: $550 – $3,250

Questions we get asked

Do you work in all of Conshohocken?

Yes, the whole borough, from the riverfront and Washington Street up the hill along Fayette Street, plus the Spring Mill area. We're based in Horsham, a short drive away.

How long does a flat roof on a row home last?

A modified bitumen torch-down roof lasts about 10 to 20+ years, depending on maintenance. Re-sealing the flashing and recoating every three years, from $350, helps it reach the long end of that.

My ceiling leaks near the wall I share with my neighbor. Whose roof is it?

It could be either one, or the seam between them. Water can travel along the party line before it drips. We'll look at both sides of the joint, with your neighbor's okay, and show you photos of where it's getting in.

How much does a new flat roof cost?

Our typical range for flat roof installation is $4,000 to $15,000. Most Conshohocken row-home roofs are small and sit in the lower part of that range. Rotted deck boards, parapet flashing and a lower back roof add to it.

Should my neighbor and I replace our roofs together?

If both roofs are about the same age, it's worth asking. One continuous roof has no seam at the party line to fail, and setup costs get shared. If only yours gets done, make sure the estimate says how the joint with your neighbor's roof is sealed.

Are you licensed and insured?

Yes. PA license #PA164826, with general liability and workers' compensation insurance. We'll show you proof before any work starts.

Related pages

• Flat Roofing: Low-slope roofs over porches, additions and row homes, where ponding water is the enemy.
• Roof Repair: Leaks, missing shingles, flashing and vents. We fix the problem and tell you honestly how much life the roof has left.
• Emergency Roof Repair: Active leak or storm damage? Call any time, day or night. We tarp it to stop the water, then make the permanent fix.
• Roof Inspection: A free, top-to-bottom look at your roof with photos, so you know what you actually need before you spend anything.
• Gutter Repair: Sagging, leaking or overflowing gutters fixed before they rot your fascia.
• Commercial Roofing: Roof repair and replacement for small commercial buildings, offices and multi-unit properties.
• Montgomery County: Where we do most of our work, from Horsham out across the county.
• Plymouth Meeting: Plymouth and Whitemarsh township neighborhoods.
• Blue Bell: Larger homes with complex rooflines and lots of valleys.
• Fort Washington: Wooded lots where trees and storms are the main roof threat.
• Ambler: Older borough homes with steep roofs and plenty of flashing.